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Mission 10 - Data quality

Learning Objective

In this mission we learn how to get an understanding of the quality of the data through common metrics.

Data

Please download the required dataset we will use: new_table_cars.xlsx

Steps

First, open the data that you want to search in.
And press on the analytics button

Image title — The analytics button

After that you see the table overview.
You can click "Data Quality" in the top menu.

Image title — Table overview

Image title — On this page are the indicators for various data quality metrics.

Image title — By clicking on one of the cleaning option buttons you'll see the data cleanser. This is a tool that can help you get the most out of your data. You'll learn more about it later.

Image title — The combined data quality score over time. As the table is modified, the score updates.

Explanation of Data Quality Metrics

In the figures above we see in the data quality tab. First the gauges show different data quality metrics including

Consistency: How consistent is the data, e.g. are there columns that mix different data types?
Completeness: How complete the data is, e.g. are there missing values?
Outliers: Are there a lot of outliers in the data?
Uniqueness: Are there a lot of redundancy in the data?
Total: A combined score to give an overview.

In each one of these metrics, a higher score indicate a better value. Well done! Now let's move on to the next mission!